Christie's described it as "one of the great masterpieces of the modern era".

The $90m price tag was all the more astonishing given the roughly $20,000 that Hockney told CNN his dealer originally sold the painting for in 1972, subsequently believing it had been undervalued. It is one of the 81-year-old artist's "pool paintings" and is considered one of his premier works.

The standing man is Peter Schlesinger, an artist and Hockney's ex-lover. After a break, he resumed the piece the following year.

"We rarely can say, "This is the one opportunity to buy the best painting from the artist", Ana Maria Celis, vice president of post-war and contemporary art at Christie's had said before the sale.